Keep an eye on the weight of the bags, too, when comparing price. We buy a rolled corn and barley mix from a local feed mill for a current price of about $8.00/80# bag. That's about the highest the price has ever been for that particular mix. I've paid as little as $4.00/80# bag in other years. It varies according to the season and the market.
I recently bought a few bags of sweet feed for my elderly horse at the local tack shop. These bags weigh 40#. They were on special in December at buy 2 bags, get two free. The cost for the two bags was about $11.00/bag, with two more free ones. At that price, I stocked up. No way am I willing to pay the regular $11.00/bag price! It's much more expensive, but I feed a scoop of it per day to this horse mixed with crushed bute tablets. It disguises the taste of the bute better than the mix without molasses.
We feed the rolled barley and corn mix along with hay to our cows in the winter when hay prices are high. The cows don't care that it doesn't have molasses in it. They see a bucket and start begging for grain.
Another local farm store chain sells a rolled corn/barley/molasses mix in 50# bags. I haven't priced it lately but the molasses mix is definitely higher.
I would suggest looking into finding a feed mill, even if you have to travel a ways. Ours is about 40 miles from here, but is on the way to the city, so I plan ahead and stock up when I'm going that way.